svn commit: r304699 - head/sys/dev/usb/input

[Bruce Evans]

Author: bde
Date: Tue Aug 23 19:50:16 2016
New Revision: 304699
URL: https://svnweb.freebsd.org/changeset/base/304699

Log:
  Fix key delay and repeat, part 1.
  
  kbdcontrol -r fast is documented to give a non-emulated atkbd's fastest
  rate of 250.34, but is misimplemented to request this as 0.0.  ukbd
  supports many nonstandard rates, although it is currently too inaccurate
  by a factor of several hundred for non-huge nonstandard rates to be
  useful.  It mapped 0.0 to 200.0.  A repeat delay of 0 means a rate of
  infinity which is quite fast, but physical constraints limit this to
  a few MHz and the inaccuracies made it almost usable.
  
  Convert 0.0 to the documented 250.34.
  
  Also convert negative args and small args to the 250.34 minimal ones,
  like atkbd does.  This is for KDSETREPEAT -- the 2 versions of the
  deprecated KDSETRAD have bounds checking.  Keep not doing any bounds
  checking or conversions for upper limits since nonstandard large
  delays are useful for testing.
  
  The inaccuracies are dependent on HZ and the timeout implementation.
  With the old timeout implementation and HZ = 1000, 200.0 probably
  worked better to emulate 250.34 than 250.34 itself.  HZ = 100 gives
  roundoff errors that accidentally reduce the inaaccuracies, and
  event timers reduce the inaccuracies even more, so 200.0 was giving
  more like itself (perhaps 215.15 on average but sometimes close to
  10 msec repeat which is noticebly too fast).  This commit makes 0.0
  noticeably too slow, like 250.34 always was.

Modified:
  head/sys/dev/usb/input/ukbd.c

Modified: head/sys/dev/usb/input/ukbd.c
==============================================================================
--- head/sys/dev/usb/input/ukbd.c	Tue Aug 23 19:41:49 2016	(r304698)
+++ head/sys/dev/usb/input/ukbd.c	Tue Aug 23 19:50:16 2016	(r304699)
@@ -1887,17 +1887,14 @@ ukbd_ioctl_locked(keyboard_t *kbd, u_lon
 		if (!KBD_HAS_DEVICE(kbd)) {
 			return (0);
 		}
-		if (((int *)arg)[1] < 0) {
-			return (EINVAL);
-		}
-		if (((int *)arg)[0] < 0) {
-			return (EINVAL);
-		}
-		if (((int *)arg)[0] < 200)	/* fastest possible value */
-			kbd->kb_delay1 = 200;
-		else
-			kbd->kb_delay1 = ((int *)arg)[0];
-		kbd->kb_delay2 = ((int *)arg)[1];
+		/*
+		 * Convert negative, zero and tiny args to the same limits
+		 * as atkbd.  We could support delays of 1 msec, but
+		 * anything much shorter than the shortest atkbd value
+		 * of 250.34 is almost unusable as well as incompatible.
+		 */
+		kbd->kb_delay1 = imax(((int *)arg)[0], 250);
+		kbd->kb_delay2 = imax(((int *)arg)[1], 34);
 		return (0);
 
 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \